Googletest as a Zephyr module for native_posix target #nrf52


I'm new to Zephyr and am trying to get a Linux VM hosted native_posix unit test build environment set up for our Zephyr nRF52 embedded project. 

I've set up the Zephyr SDK and west native_posix (& qemu_x86) build environment and can build and run the samples and a simple hello world test under my Ubuntu 20.04 Linux VM.

We'd like to use GoogleTest/Mock for our unit test environment within the Zephyr native_posix environment. Has anyone here got that working? I've got some way following this StackOverflow post unit-testing-c-code-into-zephyr-with-googletest , but unfortunately it does not provide details of the module.yml and Kconfig file contents. I don't yet know enough to fill them in myself and west / cmake reports that my googletest module is "not a valid zephyr module".

Any help or pointers would be appreciated!